Attachment 78354 Details for Bug 63447 – Potential fix

[patch] Potential fix

0001-egl-dri2-Fix-min-max-swap-interval-of-configs.patch (text/plain), 2.77 KB, created by Chad Versace on 2013-04-23 03:00:40 UTC

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Creator: Chad Versace

Created: 2013-04-23 03:00:40 UTC

Size: 2.77 KB

patch

obsolete

>From 72a90102d5f510e3635007bb761d5f9857888831 Mon Sep 17 00:00:00 2001
>From: Chad Versace <chad.versace@linux.intel.com>
>Date: Tue, 23 Apr 2013 04:17:48 +0200
>Subject: [PATCH] egl/dri2: Fix min/max swap interval of configs
>
>The commit below exposed a bug in dri2_add_config.
>
>    commit 3998f8c6b5da1a223926249755e54d8f701f81ab
>    Author: Ralf Jung <post@ralfj.de>
>    Date:   Tue Apr 9 14:09:50 2013 +0200
>
>	egl/x11: Fix initialisation of swap_interval
>
>This little code snippet near the bottom of dri2_add_config,
>
>    if (double_buffer) {
>       ...
>       conf->base.MinSwapInterval = dri2_dpy->min_swap_interval;
>       conf->base.MaxSwapInterval = dri2_dpy->max_swap_interval;
>    }
>
>it never did what it claimed to do. The assignment never changed the value
>of conf->base.MaxSwapInterval, because dri2_dpy->max_swap_interval was,
>until the above exposing commit, unitialized here. That is,
>conf->base.MaxSwapInterval was 0 before and after assignment. Ditto for
>the min swap interval.
>
>Above the troublesome code snippet, the call to _eglFilterArray rejects
>the config as unmatching if its swap interval bounds differ from the base
>config's.  Before the exposing commit, at the call to _eglFilterArray, the
>swap interval bounds were always [0,0], and hence no config was rejected
>due to swap interval.
>
>After the exposing commit, _eglFilterArray incorrectly rejected some
>configs, which prevented dri2_egl_config::dri_double_config from getting
>set for the rejected config, which resulted in a NULL pointer getting
>passed into dri2CreateNewDrawable, and then segfault.
>
>The solution: set the swap interval bounds before _eglFilterArray.
>
>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=63447
>Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
>---
> src/egl/drivers/dri2/egl_dri2.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
>diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
>index 06a21d7..1011f27 100644
>--- a/src/egl/drivers/dri2/egl_dri2.c
>+++ b/src/egl/drivers/dri2/egl_dri2.c
>@@ -221,6 +221,9 @@ dri2_add_config(_EGLDisplay *disp, const __DRIconfig *dri_config, int id,
>    base.RenderableType = disp->ClientAPIs;
>    base.Conformant = disp->ClientAPIs;
> 
>+   base.MinSwapInterval = dri2_dpy->min_swap_interval;
>+   base.MaxSwapInterval = dri2_dpy->max_swap_interval;
>+
>    if (!_eglValidateConfig(&base, EGL_FALSE)) {
>       _eglLog(_EGL_DEBUG, "DRI2: failed to validate config %d", id);
>       return NULL;
>@@ -268,9 +271,6 @@ dri2_add_config(_EGLDisplay *disp, const __DRIconfig *dri_config, int id,
> 
>    if (double_buffer) {
>       surface_type &= ~EGL_PIXMAP_BIT;
>-
>-      conf->base.MinSwapInterval = dri2_dpy->min_swap_interval;
>-      conf->base.MaxSwapInterval = dri2_dpy->max_swap_interval;
>    }
> 
>    conf->base.SurfaceType |= surface_type;
>-- 
>1.8.1.4
>

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